F2F2 Issue Discussions

This wiki page captures issues discussed at the F2F2, along with prevailing consensus of F2F2 attendees. We'd like to concretely resolve these as soon as possible, so we ask for feedback from WG members, particularly if you disagree with the consensus of F2F attendees.

ISSUE-11: Implicit grouping

Consensus on prohibiting projecting variables/functions on variables that are not included in the group by clause. Details are pending discussion of ISSUE-41.

ISSUE-12: HAVING vs. FILTER as keyword for limiting aggregate results

General consensus in favor of using "FILTER" as the keyword, with bglimm preferring "HAVING".

(In favor: SteveH, kasei, axel, LeeF, pgearon)

DISTINCT in aggregate functions

Consensus on allowing DISTINCT with multiple arguments to aggregate functions. DISTINCT in this case passes just the DISTINCT tuples into the aggregate function (for each group).

(In favor: SteveH, kasei, axel, LeeF, pgearon)

Star (asterisk) in aggregate functions

Consensus around only allowing asterisk as an argument to COUNT.

(In favor: SteveH, kasei, axel, LeeF, pgearon)

ISSUE-15: Syntax for custom aggregates

Mild opinion in favor of having no keyword or special syntax for custom aggregate functions (LeeF, Axel, SteveH, kasei). pgearon (and observer dajobe) expressed mild preference for a keyword to introduce custom aggregates. Consensus that this should be advice to the editors.

ISSUE-16: Mixed datatypes with built-in aggregates

Consensus that MIN/MAX should use same semantics as ORDER BY, with parts (e.g. ordering xsd:string and xsd:dateTime) being undefined/implementation defined. (SteveH, kasei, axel, LeeF, bglimm).

Consensus that SUM/AVG should use same semantics as + (SteveH, kasei, axel, LeeF, bglimm).

What happens with type errors that are projected?

Consensus that type errors that are projected should result in that solution being discarded. (SteveH, kasei, axel, LeeF, bglimm, iv_an_ru (on IRC))

Trapping type errors?

Consensus that COALESCE is a good way to trap errors. (SteveH, kasei, axel, LeeF)